In a backlight unit for liquid crystal display included in a liquid crystal display device, a unit assembly is performed to assemble a middle frame and a rear frame by fitting a fitting hole provided in the middle frame with a narrowing part provided in the rear frame as a fitting claw for purpose of reducing a total number of components and improving an assembly operation. Herein, the middle frame is also referred to as a mold frame when it is formed by a resin molded using a mold.
As such a liquid crystal display device, Japanese Patent Application Laid-Open No. 2007-232812 discloses a configuration of fixing a pair of frames using an engaging protrusion and an engaging hole as a frame structure used for the liquid crystal device, for example. Particularly disclosed is a configuration that an upper end part of one frame in which the engaging protrusion is formed is in direct contact with a side surface of the other frame for purpose of preventing a backlash at the time of fixing the frames.
Japanese Patent Application Laid-Open No. 2012-008305 discloses a configuration of fixing a pair of frames using an engaging protrusion and an engaging hole as a frame structure used for the liquid crystal device in a manner similar to Japanese Patent Application Laid-Open No. 2007-232812. Japanese Patent Application Laid-Open No. 2012-008305 discloses a configuration that the upper end part of the frame in which the engaging protrusion is formed is not in direct contact with the other frame, differing from the case of Japanese Patent Application Laid-Open No. 2007-232812, but is wholly separated from each other in a state where the engaging protrusion and an engaging hole engage with each other,
Japanese Patent Application Laid-Open No. H09-197383 discloses a configuration of a liquid crystal display device that a positioning protrusion is provided in an upper end part of a shield case housing part as a frame in which a protrusion for preventing the frame from falling off is formed. The positioning protrusion is provided to engage with and be fixed to a positioning engaging hole provided in a shield case cover which is an external frame formed by combining the frames.